New BG-93 M3 do not register with foreign SIMs


I have an odd problem with a new delivery lot of BG95-M3. The new modules do not register with SIMs of foreign providers. AT+CREG=2;+CREG? permanently responses +CREG: 2,2 (trying to register). The modules are working fine with SIMs of a local provider. After registering with a SIM of the local provider, switching the module off, changing to the foreign SIM and start the module again, it exactly registers one time. All further trials fail. When using manual operator selection with AT+COPS, the new modules register (roaming) to this local network. But with AT+COPS=0 they don’t. As we do not know, in which country our products are used, we cannot work with manual provider selection. I reproduced the problem with foreign SIMs of different countries.

Modules of earlier delivery lots are working fine with all tested SIMs, local and foreign. In my normal setup sequence, the factory settings regarding operator selection are not changed.

We have the same SIMs, the same location, the same setup, the same hardware PCB and the same module version. Why do the modules behave differently? Can there be any permanent setting, that causes this problem?

New and former module’s version: BG95M3LAR02A03
One of the former module’s IMEI: 863257068151275
One of the new module’s IMEI: 869084062044023

Thank you for your help!

Does the AT command AT+QCFG="roamservice" return a value on these modules?

No, the response to AT+QCFG=“roamservice” is “ERROR” with both module lots. And in the responses to “AT+QCFG=?”, there is no entry “roamservice”.
By the way, I found out that the modules of the new delivery lot have much more answers to “AT+QCFG=?”:
bandrestore, snrscan, uartcfg, emmcause, sibinfo, emmtimer, msclass, fgiconfig, sim/onchip, cmux/signal, dgbctl.
Hence, there must be some differences in the modules, although they have the same version numbers.

With AT+CSUB I found out, the former (working) modules have the sub version V02 and the new ones (not working) V03.
Can someone explain the difference? Are there release notes?

Is there a network scan that already works, it the module is not registered to a network?

AT+COPS=? should work. Give it time to complete its scan.

It works, many thanks.